FIG. 1 illustrates a conventional document scanner. In the conventional scanner, a light source 11 is used to illuminate a document 3 having an image thereon. The conventional document scanner also includes a glass platen 5 upon which the document 3 rests and a platen cover 1. FIG. 1 also shows the optical center line 9 for the conventional document scanner.
To scan the image on the document, the light source 11 illuminates the document 3 through the glass platen 5 such that the light reflected from the document 3 passes through on optical lens system 7. The optical lens system 7 directs the reflected light to either a photosensitive recording medium, a CCD sensor, or a full width array sensor. If the reflected light is directed to a photosensitive recording medium, a latent image of the document 3 is developed thereon and is subsequently transferred to a copy substrate. On the other hand, if the reflected light is directed to a CCD sensor or a full width array sensor, the light reflected from the document 3 is converted into electronic signals forming image data which electronically represent the document 3.
To provide a full scanning of the document 3, either the document 3 is moved relative to the light source 11 and the components which receive the reflected light, or the light source 11 and the components receiving the reflected light are moved relative to the document 3.
FIG. 2 illustrates, in more detail, the light source 11 for a conventional document scanner. This conventional light source includes a fluorescent lamp 111 which produces the light coming from the light source 11. Attached to either end of the fluorescent lamp 111 are lamp bases 110 which include electrical pins 118. These electrical pins provide an electrical conduit for the fluorescent lamp so that the fluorescent lamp can receive the proper electrical power. These pins 118 also provide mechanical support by holding the fluorescent lamp 111 securely in place.
For the fluorescent lamp to be fully functional and secure, the pins 118 are placed into fluorescent lamp holders 117 which provide the mechanical support for the fluorescent lamp as well as the electrical terminals which provide the electrical power to the fluorescent lamp. The fluorescent lamp holders 117 are each connected to a pair of electrical leads 116 which are in turn connected to a power source.
The fluorescent lamp 111 is also substantially covered by a heater blanket 112 which includes a heater element 113. The heater blanket 112 may include a small slit or be transparent to allow the light produced by the fluorescent 111 to pass through the heater blanket 112 and illuminate the document 3. The heater blanket 112 is provided to prevent undesirable cold spots within the fluorescent lamp and to enable the fluorescent lamp to produce a more stabilized light.
The heating element 113 is connected to a power source through contacts 114 and electrical leads 115. Thus, to properly assemble a conventional light source in a conventional document scanner, the fluorescent lamp 111 is placed in the fluorescent lamp holders 117 and the leads 115 are soldered to the heating element at contacts 114 located on the fluorescent lamp 111.
Utilizing such a conventional light source as described above, with respect to FIGS. 1 and 2, the replacement of the light source becomes problematic. More specifically, to replace the conventional light source, the user must connect electrical leads to the heating element at the appropriate connecting pads located on the lamp which increases the time for replacement routines and can cause possible damage to the lamp.
Therefore, it is desirable that the light source for a document scanner be constructed such that the fluorescent lamp can be replaced without requiring the connection of the electric leads to the heating element through connection pads located directly on the lamp and enabling the fluorescent lamp to be easily connected or disconnected from the document scanner to facilitate a faster replacement of the lamp. It is further desirable to constructed an integrated heater/lamp power harness approach which reduces the variability of resistance of achieved through the elimination of the conventional intermediate connector.